Steroids and steroidal sapogenins: hecogenin, guggulosterone, withanolides MCQs With Answer

Steroids and steroidal sapogenins: hecogenin, guggulosterone, withanolides MCQs With Answer

This quiz collection is designed for M.Pharm students preparing for advanced phytochemistry examinations. It focuses on steroidal compounds and sapogenins—especially hecogenin, guggulosterone (guggulsterones) and withanolides—covering their natural sources, structural classes, biosynthetic origins, isolation techniques, analytical identification, chemical transformations and pharmacological actions. Questions emphasize mechanistic understanding, practical analytical methods (TLC/HPLC/NMR/MS), and the role of sapogenins in steroid semi-synthesis and drug development. Use these MCQs to test recall, apply conceptual knowledge to laboratory and formulation contexts, and strengthen exam readiness through clinically and industrially relevant scenarios.

Q1. Which plant is a major commercial source of hecogenin used for steroid semi-synthesis?

• Agave sisalana (sisal)
• Dioscorea villosa (wild yam)
• Withania somnifera (ashwagandha)
• Commiphora mukul (guggul)

Correct Answer: Agave sisalana (sisal)

Q2. Hecogenin is classified chemically as which type of steroidal sapogenin?

• Spirostanol sapogenin
• Dammarane triterpenoid
• Seco-steroid sapogenin
• Cardenolide glycoside

Correct Answer: Spirostanol sapogenin

Q3. The term “guggulosterone” in phytochemical literature most closely corresponds to which class of compounds from Commiphora mukul?

• Steroidal antagonists of nuclear receptors (guggulsterones, E/Z isomers)
• Triterpenoid saponins with sugar moieties
• Flavonoid glycosides with antioxidant activity
• Iridoid monoterpenes

Correct Answer: Steroidal antagonists of nuclear receptors (guggulsterones, E/Z isomers)

Q4. Which analytical test is classically used as a rapid colorimetric indication of steroidal sapogenins on TLC plates?

• Liebermann–Burchard reagent test
• Dragendorff’s reagent
• Folin–Ciocalteu reagent
• Molisch test

Correct Answer: Liebermann–Burchard reagent test

Q5. In sapogenin isolation from plant material, which step is typically performed to liberate the sapogenin aglycone from its glycoside form?

• Acid hydrolysis of the saponin extract
• Enzymatic methylation of glycosides
• Base-catalyzed transesterification
• Direct solvent extraction without hydrolysis

Correct Answer: Acid hydrolysis of the saponin extract

Q6. Which structural feature distinguishes withanolides from typical plant sterols?

• Presence of an α,β-unsaturated lactone side chain
• Absence of the steroidal tetracyclic nucleus
• High content of glycosidic sugar residues
• Cardenolide-like lactone fused at C17 only

Correct Answer: Presence of an α,β-unsaturated lactone side chain

Q7. A key pharmacological action attributed to guggulsterones is their interaction with which nuclear receptor affecting cholesterol metabolism?

• Farnesoid X receptor (FXR)
• Peroxisome proliferator-activated receptor gamma (PPARγ)
• Estrogen receptor alpha (ERα)
• Glucocorticoid receptor (GR)

Correct Answer: Farnesoid X receptor (FXR)

Q8. Which chromatographic technique is most commonly applied for quantitative fingerprinting of withanolides in commercial Withania extracts?

• HPTLC or HPLC with UV/diode-array detection
• Paper chromatography with iodine staining
• Gel permeation chromatography with refractive index detector
• Thin-layer chromatography without derivatization only

Correct Answer: HPTLC or HPLC with UV/diode-array detection

Q9. Which step in semi-synthetic steroid production most often utilizes sapogenins like hecogenin or diosgenin?

• Oxidative cleavage and rearrangement to obtain appropriate C17 side chains
• Direct glycosidation to produce steroidal saponins
• Photochemical isomerization to produce ergosterols
• Hydrogenation to saturate all double bonds without functionalization

Correct Answer: Oxidative cleavage and rearrangement to obtain appropriate C17 side chains

Q10. Withaferin A, a major withanolide, is particularly noted for which biochemical action relevant to anticancer studies?

• Inhibition of NF-κB signaling and disruption of cytoskeletal proteins
• Direct agonism of opioid receptors
• Strong reversible inhibition of acetylcholinesterase
• Potent inhibition of HMG-CoA reductase

Correct Answer: Inhibition of NF-κB signaling and disruption of cytoskeletal proteins

Q11. Which mass spectrometric fragmentation pattern is typically helpful in distinguishing spirostanol sapogenins like hecogenin from furostanol types?

• Characteristic spiroketal-derived fragment ions (loss of side-chain fragments around C22-C26)
• Presence of high molecular-weight sugar cluster ions
• Dominance of intact molecular ion with no fragment ions
• Cleavage only at the A-ring producing steroidal ketone fragments

Correct Answer: Characteristic spiroketal-derived fragment ions (loss of side-chain fragments around C22-C26)

Q12. During quality control of Commiphora mukul resin, which analytical endpoint is commonly used to standardize guggul preparations?

• Content of E- and Z-guggulsterone isomers determined by HPLC
• Total flavonoid content measured by Folin–Ciocalteu
• Total ash content alone
• Saponin index measured by foaming only

Correct Answer: Content of E- and Z-guggulsterone isomers determined by HPLC

Q13. Which biosynthetic precursor class gives rise to withanolides in plants?

• Sterol pathway intermediates (e.g., lanosterol/cycloartenol derivatives)
• Shikimate-derived phenylpropanoids
• Polyketide-derived macrolides
• Alkaloid terpenoid hybrids from tropane pathway

Correct Answer: Sterol pathway intermediates (e.g., lanosterol/cycloartenol derivatives)

Q14. Which chemical modification is commonly carried out on hecogenin to render it suitable as a precursor for corticosteroid semi-synthesis?

• Oxidation of the side chain and formation of a 17-keto functionality
• Glycosylation at C3 to increase polarity
• Epoxidation of the B-ring double bond only
• Complete hydrogenation of the tetracyclic nucleus

Correct Answer: Oxidation of the side chain and formation of a 17-keto functionality

Q15. Which safety or regulatory concern has been associated with guggul-derived supplements in clinical practice?

• Interference with thyroid function tests and drug interactions (e.g., warfarin)
• High risk of causing hypoglycaemia in all patients
• Universal hepatotoxicity in low doses
• Immediate anaphylaxis upon topical exposure

Correct Answer: Interference with thyroid function tests and drug interactions (e.g., warfarin)

Q16. For isolation of withanolides from Withania somnifera roots, which solvent system is frequently chosen for initial extraction due to polarity of withanolides?

• Methanol or ethanol (polar organic solvents)
• Hexane (non-polar solvent)
• Petroleum ether only
• Water exclusively at room temperature

Correct Answer: Methanol or ethanol (polar organic solvents)

Q17. Which spectral feature in 1H-NMR is commonly used to identify the presence of an α,β-unsaturated lactone in withanolides?

• Downfield olefinic proton signals (δ 5.5–7.5) coupled with deshielded lactone carbonyl signals in 13C-NMR
• Strong methyl singlets only at δ 0.5–1.5 with no olefinic signals
• Only broad singlet at δ 3.3 indicating sugar residues
• Complete absence of any proton signals in the olefinic region

Correct Answer: Downfield olefinic proton signals (δ 5.5–7.5) coupled with deshielded lactone carbonyl signals in 13C-NMR

Q18. Which pharmacokinetic characteristic has limited reproducible lipid-lowering efficacy of guggul-derived products in clinical trials?

• Poor oral bioavailability and variability due to isomeric composition
• Extremely long half-life leading to accumulation in tissues
• Complete first-pass conversion to inactive glycosides
• Exclusive excretion unchanged in feces without absorption

Correct Answer: Poor oral bioavailability and variability due to isomeric composition

Q19. In forced degradation studies of withanolide-containing formulations, which condition is most likely to cause lactone ring opening and loss of activity?

• Strong alkaline hydrolysis
• Storage at –20 °C in inert atmosphere
• Exposure to non-polar solvents like hexane
• Lyophilization under vacuum

Correct Answer: Strong alkaline hydrolysis

Q20. Which approach is most appropriate to confirm the absolute configuration and stereochemistry of a novel steroidal sapogenin isolated from plant material?

• Combined techniques: 1D/2D NMR, HR-MS, X-ray crystallography or CD (where possible)
• Only UV–Vis spectrophotometry at 280 nm
• Simple melting point determination alone
• Paper chromatography Rf comparison with a single standard

Correct Answer: Combined techniques: 1D/2D NMR, HR-MS, X-ray crystallography or CD (where possible)

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